Objective c Split String Issue - ios

Question

I'm trying to split a string into an NSArray, however I'm having an issue ignoring strings that have speech marks in.
For example
NSString *example = #"100 200 300 \"TEST ITEM\" 500";
NSArray *array = [example componentsSeparatedByString:#" "];
However the array obviously gets created as 100, 100, 300, "Test, ITEM", 500. Is it possible to treat anything with " " as one?
Thanks

Answer 1

You could use a well known CSV Parser which can be configured to use spaces as separators, and will treat double-quotes correctly. That assumes you want usual CSV-handling like escaping of double-quotes inside double-quoted strings, etc.
Otherwise, you'll probably need to write the parsing logic yourself; take a look at NSScanner, which would let you read up to a space or double-quote, look at what you get back, and then read to the next space/double-quote, etc.
Example:
#interface ItemParser : NSObject<CHCSVParserDelegate>
- (NSArray *)itemsFromString:(NSString *)input;
#end
#implementation ItemParser {
NSMutableArray *_results;
}
- (NSArray *)itemsFromString:(NSString *)input {
_results = [NSMutableArray array];
NSStringEncoding encoding = [input fastestEncoding];
NSInputStream *stream = [NSInputStream inputStreamWithData:[input dataUsingEncoding:encoding]];
CHCSVParser *parser = [[CHCSVParser alloc] initWithInputStream:stream usedEncoding:&encoding delimiter:' '];
parser.delegate = self;
[parser parse];
return _results;
}
- (void)parser:(CHCSVParser *)parser didReadField:(NSString *)field atIndex:(NSInteger)fieldIndex {
[_results addObject:field];
}
#end
You'd use it like this:
NSString *example = #"100 200 300 \"TEST ITEM\" 500";
ItemParser *parser = [[ItemParser alloc] init];
NSLog(#"%#", [parser itemsFromString:example]);

Answer 2

Here's an NSString category that uses an NSScanner to split a string into search terms, respecting various types of quote pairs: "" '' ‘’ “”
Usage:
NSArray *terms = [#"This is my \"search phrase\" I want to split" searchTerms];
// results in: ["This", "is", "my", "search phrase", "I", "want", "to", "split"]
Code:
#interface NSString (Search)
- (NSArray *)searchTerms;
#end
#implementation NSString (Search)
- (NSArray *)searchTerms {
// Strip whitespace and setup scanner
NSCharacterSet *whitespace = [NSCharacterSet whitespaceAndNewlineCharacterSet];
NSString *searchString = [self stringByTrimmingCharactersInSet:whitespace];
NSScanner *scanner = [NSScanner scannerWithString:searchString];
[scanner setCharactersToBeSkipped:nil]; // we'll handle whitespace ourselves
// A few types of quote pairs to check
NSDictionary *quotePairs = #{#"\"": #"\"",
#"'": #"'",
#"\u2018": #"\u2019",
#"\u201C": #"\u201D"};
// Scan
NSMutableArray *results = [[NSMutableArray alloc] init];
NSString *substring = nil;
while (scanner.scanLocation < searchString.length) {
// Check for quote at beginning of string
unichar unicharacter = [self characterAtIndex:scanner.scanLocation];
NSString *startQuote = [NSString stringWithFormat:#"%C", unicharacter];
NSString *endQuote = [quotePairs objectForKey:startQuote];
if (endQuote != nil) { // if it's a valid start quote we'll have an end quote
// Scan quoted phrase into substring (skipping start & end quotes)
[scanner scanString:startQuote intoString:nil];
[scanner scanUpToString:endQuote intoString:&substring];
[scanner scanString:endQuote intoString:nil];
} else {
// Single word that is non-quoted
[scanner scanUpToCharactersFromSet:whitespace intoString:&substring];
}
// Process and add the substring to results
if (substring) {
substring = [substring stringByTrimmingCharactersInSet:whitespace];
if (substring.length) [results addObject:substring];
}
// Skip to next word
[scanner scanCharactersFromSet:whitespace intoString:nil];
}
// Return non-mutable array
return results.copy;
}
#end